Piston slap

[Jon]

Just stripped the 600ss down and discoverd that the front or horizontal piston has sufferd a bit of piston slap. The machine marks that travel all around the piston have worn off on the topside. My querie is, what is the solution. Is it a case of rebore,new piston and rings. Or can you get away with new rings only?

[yeti]

You really need to meausure the bore and make sure it's not above limits. Is there a noticable lip at the top of the bore where the piston reaches it's max? Good chance of it wasn't burning oil that you could get away with new rings, but don't quote me.

[yeti]

You really need to measure the bore and make sure it's not above limits. Is there a noticable lip at the top of the bore where the piston reaches it's max? Good chance of it wasn't burning oil that you could get away with new rings, but don't quote me.

[Jon]

No sign of a lip John just the piston slightly polished on the top edge.

[tranquil_rage]

Get the vernier gauges out and check clearances. It's the only way to be sure about the bore and the piston itself. If both are within limits then new rings should be the sum of it.

[Jon]

Get the vernier gauges out and check clearances. It's the only way to be sure about the bore and the piston itself. If both are within limits then new rings should be the sum of it.


Thx TR

[rockhopper]

I thought it was a common problem on these engines and nothing to worry about - chances are it will start doing it again almost as soon as you have fixed it.

[rockhopper]

Apart from the machining marks wearing off is there any sign of compresion leaking past the piston? If not then there is nothing to be gained by new rings.

[AK]

Jon did you listen to most of the bikes in the paddock this year.
most have a bit of piston slap on the front cyl.
froggys was so bad i couldnt listen to it in april on the dyno but he has raced it all year and it hasnt got any worse.
as you have it apart, if it was me i would put a piston kit in it which includes piston, rings and pin which is not a lot more expensive than the rings. make sure you get the right year tho as there are 2 different engines as we know from the big bore kits last year!
otherwise just carry on using it like everyone else seems to do:D

[phil_h]

You are unlikely to get any wear on the bore because its plated, so dont ask for the barrel to be rebored :o
All the essesses have a tendancy to slappy pistons, and the noisy ones are the most powerful !
If you are not using oil, and the noise gets less when the engine (piston !) is hot, then dont worry, they really all do that sir.
If you're really worried, I could sell you some used spares, but they'll be the same within a 500 miles.

[Scooter916]

Echo Alan and Phil. Sounds awfull but normal.
Glyn

[Jon]

Well food for thought. I think I'm going to leave it as it is. I might just ship the heads and barrels off to nelly for a health check.

[CipiVTS]

How can you distinguish piston slap apart from the other engine noises?

[Scooter916]

How can you distinguish piston slap apart from the other engine noises?
Experience I would say, Been doing this job 20 years now but still get caught out occasionally.
If your worried about yours, have someone who knows take a listen to it.
Glyn

[phil_h]

Well for a start,
it gets quieter as the piston gets hotter,
it gets quieter under load compared to at idle,










and it sounds like a piston skirt slapping the bore :lol:


ie - like the side of an aluminium dish-thing knocking against something solid ;)